Wireless telegraphy.



G. MARGONI.

WIRELESS TELEGRAPHY.

APPLIUATIOH nun Mn 15, 1909.

954,641 Patented Apr. 12, 1910.

2 SHEETS-SHEBT l.

I E W A/Tys G. MARCUNI. WIRELESS TELBGEAPHY.

nrmoumn FILED MAY 15. 1909.

954,641 Patented Apr. 12, 1910.

2 SHEETS-BHBET 2.

UNITED STATES PATENT OFFICE. a

, enema comr'an or AMERICA,

NEW JERSEY.

To all whom it may concern;

-Be it known that I, GUGLIELMO MABOONI. LL. 1)., DwSfh, a-subject ofthe King of Italy, residing at Watergate-House, AdeL p'hi,"Lond0n, England, have invented new and useful Improvements in. Wireless Telegraphy o'f which the-following is aspecificatio'n. V

It has before been suggested to connect the aerial ofa wirelesstelegraph' station to the'transmitt'ing and to the reeeivingcircuits for small portions of-a' second alternately and successivelyfor the purfiose'ofduplex telegraphy-but heretoforeit has been necessary to synchronize the instruments at the two stations in such a manner that when at one station the transmitter is operative and thereceiv-er'ino erative at the other'station the receiver shal be operative and the'transniitter inoperative v L The object f this invention is to avoid diflicult to" attain in practice; and "fonthis purpose there is provided at eachcf 'two'o'r more stations, transmitting receivin fappar'atus which are rendered o erative an ino erative alternatelyft o e'ac other in ItiPld su cession, the operative periods of the t faiismittinga paratusbeing considerably shorter than t 1058 of the receiying', apparatus, "viihilethe transmitting apparatus is such that the making of each sign occupies several operative eriods and that" such operativ'e';periods o not synchi ni ze' with {use of the apparatus at any 0 'theother carrying out the invention it is efferred to employ for 'tran's1i ii ;ting, the knoyvn apparatus whicliconsists of a'rotating disk having teeth or studs which cause groups of electrical oscillations to'be generrated at regular short intervalsand foi'the purpose'o the present invention one or more eommutators are rotated synchronously with 'thel studded wheel tuch'a wa that they cause the receiving apparatus to olperatlv'e only during the interval between 't 1'e""diseharges and to be rendered inoperae *t'i'v'e during thershortperiods whnlthe 'dischargesa're'taking' zilaee. I

5 The commutators rnay made to rotate. with thestudded Wheel orv i nchf i i skew r-by v or by drivih them by a chronous motor which is wol ed from an aternatormliehan- WIRELESS mn iemrnix s reciflcaticii of Lcttcrs i'ntent. Application ifllBdJKB-Y 15 1909 56118-1 No 98,095. 1 i t "rendered a coupling them; mechanically or new YORK, N. L, A coaromuron or I Patented Apr. 12,1910.

ica'lly coupled to the disk. The commutators may render the receiver periodicallyinoperative either directly or indirectly as by periodically making or breakinga local "cir- *cu-it or an intermediate circuit which 1 renders the receiver inoperative or by any co'm bination of'these localor' intermediate .cir-

cuits. Or the eon' mutator's may render the receiver fe'riodleally inoperative bycausing the eerie to be connected alternately to the transmitting and receiving apparatus. Or

distance rein the transmitting aerial may be used for receiving and the commutator made to periodically-disconnect the receiving apparatus ahdli'f desirable'earth the receiving-aerial during the short'per'iods the transmitting aerialis radiating. y

" *VVhether ifsin one or two aerials the comn'lutatoris pret arably caused 'to render the receiver periodically inoperative either by eeiver; and indicator which it 'actuate's or 'byany' combination of theseinethods theexact" method er'nplollyl ed dependin mainly upon the nature or t e receiverand indicator nearly the seine as the ratio of the timebetvt'een two discharges to the time between two dischar charge and a I ,disks' at the stations sufficient to insurethat more than one discharge takes place "for every dot'si es plus the timebf dne'disbetween tvyo ration of one disehargeand the s'lieeds of the station with thefaster di's'k'will only fniss one out of nine diflOhfllFS from the'stetion with theslovver dis'k an th V .slowriifljsk'wil1;miss oneoiit "of ten diethat "es fiomthe station with the faster disk. tfiereforel every signal eonsists of more an en'tirel separate aerial at any convenient disconnecting or by short circuiting the reof the disks at the stations the same or tion from its own commutator can be e'n-'. tirely avoided. Thus supposing the interval discharges 1s ninetimesthe, (111 used. it is evident that ifthe two discharges so bymaking the speedsofthe aied interference at'either sta disks at the stations are as ten is to nine the l e sateen with the tion of the commutators is indicated than one'discharge neither station will ever miss a signal from the other.

It is sometimes desirable to inclose the receiving instruments and connections in metallic casings and tubes connected to earth in order to prevent the electric waves generated at the same station from directly afi'ecting thereceiver. It is well known that by suitable tuning, signals of diiferent wave lengths me be transmitted or received simu taneous y and. independently by any one station, and therefore any such arran ment may be used in 0011;11110171011 with the erein described method or simultaneous transmission and rece tion of signals at the same station to enablie several to be transmitted and received simultaneously and independently at any one station either to or from one or several other stations.

he accompanying figures show four s stems of connections m accordance with t is invention. In all of these figures '1 represents a disk carrying studs 2 w ich discharge the condenser 3 through the prima 4 of an oscillation transformer at regu er intervals when passing between the side disks 5 and 6. The disk is won at any desired speed b a suitable motor which is not shown in the rawin 7 and 8 in t and 9 in Fig. 2 are commutators which may conveniently consist of bars of copper or any suitable conductor mounted on ,a drum of suitable nonconducting materials.

In the drawings the nonconducting brshading. Each commutator has the semi number of bars as there are studs on the disk and each is provided with one or more pairs of brushes 10 and 11 each pair being cdnnected together atthe commutator here.

In ractice each brush is mounted u n a holder which can be rocked forwar or backward upon the shaft and thus advance or retard the time of contact of the brush with the commutator bar. Fig. 1 shows two commutators 7 and 8 coupled to the disk 1 through an insulating coupling. 12 is the aerial; 13 the secondary of the oscillation transformer, 14 the earth. The brush 11 of the commutator 7 is connected to the bottom of the oscillation transformer secondary 13 and the brush 10 is connected to earth.

.The brush 10 of the commutator 8 isconnected to the bottom of the secondary 13 and the brush 11 is connected to the receiver 15.

The commutator 7 has narrow bars and the commutator 8 has wide bars as indicated.

The brushes of the commutator 7 are adusted so that they are connected ther y the commutator bars inst before an' dieconnected just after the studs 2 pass between e Figures 1, 3 and 4 and 7, 8.

regular intervals by mechanically to protect the the side disks 5 and 6. The brushes of the commutator 8 are adjustedso that they are connected together by the commutator bars ust after the brushes of the commutator 7 are disconnected and are disconnected 'ust before the brushes of 7 are connected. he result is that theaerial is connected through the secondary 13 to earth and disconnected from the receiver 15 durin the time a stud 2 is passing between the side disks 5 and 6 that is during the time of discharge and connected through the secondar 13 to the receiver 15 during the intervals tween the discharges.

Fig. 2 shows three oommutators 7 9 mechanically coupled to the disk 1 through an insulating cou ling. The commutator 7 connects the aerial 12 through the transformer secondary 13 to earth during the time the studs are passing between the side disks 5 and 6. The commutator 8 connects the aerial directly to the receiver 15 just after it is disconnected from the oscillation transformer secondary 13 by the commutator 7 and disconnects it from the receiver lust before it is connected again to the oscil-- ation transformer secondary. The commutator 9 short indicator 16 circuits the'receiver 15 and the during the time the commutator .7 connects the aerial to the transformer secondary that is duringthe time the discharges are taking place.

Fig. 3 shows two commutators7 and 8 mechanically coupled to a disk 1 through e an insulating c6upling. In this system transmitting aerial 1 permanentl connected through the oscillation trans ormer secondary 13 and through a small s ark gap 18 to earth. A separate :aerial 9 is used for receiving; The commutator 7 disconnects this receiving-aerial from thereceiver 15 during the time the discharges are taking place and connects it to,15 uring the interval betweenthe discharges. The commutator 8 short circuits the and the indicator 16 durin the aerial 19 is disconnected 15 by the commutator 7.

F 4 shows two commutator-s 7 and 8 coup from an alternator 21 coupled to the disk 1 throu h an insulated coupling. A separate eerie? 19 is used for receiving and the commutators 7 and 8 perform the same operat'on as in Fig. 3. The receivin apparatus and any commutators connecte to It are .inclosed 1n a metal room or box indicated by 22 which is earthed fieriodsthe 0m t e recelver powerful inductive effects of the aerial when radiating. All the necessaryswires are taken ings this room or box through insulating tn l j The disk may be re laced by any suitabl moving terminals suc Od as by bars or r 8'and' receiver 15 ed to a synchronousmotor 20 driven which is mechanicallyreceiving apparatus from the reciprocated by cams or eccentrics on a rol tating shaft. Similarly the commu'tators may be replaced by any reciprocating mechanism which can be made to reciprocate synchronously with the mechanism controlling the discharges in the condenser circuit inductively coupled to the aerial and which will erform the same operations as the commutators described and render the receiving apparatus operative only during the interva between the discharges.

What I claim is 1. In a station for du lex wireless telegraphy, the combination 0? a transmitter having a gap in the oscillation circuit, bridging pieces, means for very rapidly moving the bridging pieces in such manner'that they bridge the gap at regular intervals, a receiver and means for rendering the receiver inoperative when the gap is bridged and rendering it operative when the gap is not bridged.

2. The combination of a plurality of stations for duplex wireless telegraphy each comprising a transmitter having a gap in the oscillation circuit, bridging pieces, means for very rapidly moving the bridging pieces in such manner that they bridge the gap at regular intervals, a receiver and means for rendering the receiver inoperative when the gap is bridged and rendering it operative when the gap is not bridged.

3. In a station for duplex wireless teleg raphy, the combination of a transmitter conriphery, an oscillation circuit, terminals in the oscillation circuit, and means for rotating the disk rapidly between the terminals, a receiver, a commutator and means for rotatin the commutator synchronously with the disk in such manner that it renders the receiver inoperative during the times the studs bridge the gap between the terminals and render it operative during the times the studs are not bridging the gap.

4. The combination of a plurality of sta-v tions for duplex wireless telegraphy each comprising a transmitter consisting of a disk havin studs around its periphery, an oscillation circuit, terminals in the oscillation circuit, and means for rotating the disk rapidly between the terminals, a receiver, a commutator and means for rotating the commutator synchronously with the disk in such manner that it renders the receiver inoperative during the times the studs bridge the gap between the terminals and render it operative during the times the studs are not bridging the gap.

GUGLIELMO MARCONI.

Witnesses:

C. J. Kn'rrniuoen, P. H. B. SAUNDERS.

sisting of a disk having studs around. its pe- .t 

